Prototype Fidelity Ladder: Defect Detection vs Cost (2D)

This is the 2D counterpart to the 3D prototype fidelity ladder, computing the identical probability-of-detection model through a flat defect map and a scrolling cost-vs-confidence strip chart instead of a rendered bracket. Pick a fidelity stage, set how many defects were injected into the design, and run test rounds: each stage's inspection-power constant and the team-rigor slider decide the chance every still-hidden defect is caught this round, while cost and time accumulate at that stage's rate — showing why teams push cheap, rough prototypes through many test rounds before ever committing to an expensive functional build.